Bai Tou Weng Tang: A Classic Remedy for Dysentery and Heat-Related Conditions
- Health Lab
- Mar 7
- 5 min read
Updated: Apr 25
Bai Tou Weng Tang, a time-honored traditional Chinese medicine (TCM) formula, is renowned for its ability to clear heat, detoxify, cool blood, and stop dysentery. Documented in Shang Han Lun by the esteemed physician Zhang Zhongjing during the late Eastern Han Dynasty, this prescription is a cornerstone for treating dysentery caused by heat toxins.
In ancient times, dysentery was a prevalent and severe intestinal condition, marked by abdominal pain, frequent diarrhea with blood and mucus, and sometimes fever. Hot and humid environments were recognized as triggers for these symptoms, and Bai Tou Weng Tang emerged as an effective solution.
Composition of the Formula Bai Tou Weng Tang
Bai Tou Weng Tang consists of four key herbs, structured according to the TCM principle of "monarch, minister, assistant, and envoy":
Monarch Herb:
Bai Tou Weng (Pulsatilla chinensis): Targets the large intestine and liver meridians, clearing heat, detoxifying, cooling blood, and stopping dysentery. Modern research highlights its efficacy against enteritis, pneumonia, influenza, and liver damage.
Minister Herbs:
Huang Lian (Coptis chinensis): Bitter and cold, it clears heat, detoxifies, and removes dampness from the intestines.
Huang Bai (Phellodendron amurense): Also bitter and cold, it excels at clearing damp-heat and supporting detoxification.
Assistant Herb:
Qin Pi (Fraxinus chinensis): Clears heat, detoxifies, and astringes to reduce diarrhea, helping control severe dysentery symptoms. It contains active compounds like coumarins and lignins, offering anti-inflammatory, antioxidant, and anti-tumor effects.
This synergistic blend effectively addresses heat, toxins, and intestinal inflammation while stabilizing bowel function.
Pathogenesis: Understanding the Condition
The conditions treated by Bai Tou Weng Tang stem from damp-heat and epidemic toxins invading the large intestine, often in hot and humid climates. These pathogens cause stagnation of intestinal Qi, leading to inflammation and tissue damage. As heat toxins penetrate deeper, they enter the blood, resulting in severe symptoms such as:
Diarrhea with bright red blood and mucus.
Abdominal pain and tenesmus (a sensation of incomplete bowel movements).
Burning sensation around the anus.
Intense thirst, a red tongue with a yellow coating, and a slippery, rapid pulse.
These symptoms reflect the dominance of heat toxins, which Bai Tou Weng Tang targets by clearing heat, cooling blood, and restoring intestinal balance.
Bai Tou Weng Tang Therapeutic Effects
Bai Tou Weng Tang is highly effective in:
Clearing Heat and Detoxifying: Removes heat and toxins to reduce intestinal inflammation.
Cooling Blood: Alleviates blood-related symptoms like bloody diarrhea.
Stopping Dysentery: Controls diarrhea and tenesmus, promoting recovery.
Beyond dysentery, modern research reveals the formula’s broader pharmacological benefits, including anti-inflammatory, antiviral, antibacterial, antioxidant, and immune-enhancing effects. It also shows potential in combating tumors, infections, and liver damage.
Bai Tou Weng Tang Modern Applications
In contemporary medicine, Bai Tou Weng Tang is used to treat a range of conditions characterized by damp-heat and toxins, including:
Acute and bacterial enteritis
Bacillary and amoebic dysentery
Chronic ulcerative colitis
Urinary tract infections
Conjunctivitis
Arthritis and hyperuricemia
Pharmacological studies confirm its strong inhibitory effects on pathogens like Shigella dysenteriae (particularly Shigella shigella and Shigella stutzeri), as well as Staphylococcus aureus, Staphylococcus epidermidis, and Moraxella catarrhalis. However, its efficacy against Shigella flexneri, Salmonella, and Sonnei is weaker or negligible.
The formula is particularly valuable for managing acute dysentery and colitis, rapidly reducing symptoms like bloody diarrhea, abdominal pain, and tenesmus. Its anti-inflammatory and antimicrobial properties make it a versatile remedy for various heat-related infections.
Precautions for Use
When using Bai Tou Weng Tang, consider the following:
Avoid in Cold or Deficiency Conditions: The formula’s bitter and cold herbs may worsen symptoms in individuals with spleen and stomach deficiency or cold-related diarrhea.
Pregnancy Caution: Pregnant women should use it only under medical supervision to avoid potential risks to the fetus.
Weak Constitutions: Those with frail health should use reduced doses or combine with tonifying herbs to prevent excessive cooling.
Syndrome Differentiation: The formula is suited for heat-toxin dysentery but not for diarrhea caused by cold, dampness, or deficiency. Accurate diagnosis is essential.
Conclusion
Bai Tou Weng Tang remains a cornerstone of TCM for its potent ability to clear heat, detoxify, cool blood, and stop dysentery. Its historical significance, documented by Zhang Zhongjing, is reinforced by modern research confirming its antimicrobial, anti-inflammatory, and immune-boosting properties.
From acute dysentery to chronic colitis, this formula offers effective relief for heat-related intestinal conditions. However, its cold nature requires careful use, with proper syndrome differentiation and medical guidance to ensure safety and efficacy. Through thoughtful application, Bai Tou Weng Tang continues to uphold its value in both traditional and modern medicine.
Chinese Name | 白頭翁湯 |
Phonetic | Bai Tou Weng Tang |
English Name | Pulsatilla Decoction |
Classification | Heat-clearing formulas |
Source | 《Treatise on Cold Damage》Shang Han Lun《傷寒論》 |
Combination | Pulsatillae Radix (Bai Tou Weng) 2 liang (15g), Phellodendri Chinensis Cortex (Huang Bai) 3 liang (12g), Coptidis Rhizoma (Huang Lian) 3 liang (6g), Fraxini Cortex (Qin Pi) 3 liang (12g) |
Method | Decoct the medicinals with seven sheng (1400 ml) of water, and boil it until the volume reduces to about two sheng (400 ml). Filter the decoction and then take one sheng (200 ml) of the decoction warm. If recovery is not achieved with the first sheng (200 ml), then the other one sheng (200 ml) should be taken. (Modern use: use water to decoct the medicinals.) |
Action | Clears heat, resolves toxins, cools the blood, and arrests dysentery. |
Indication | This formula is indicated for heat toxin bloody dysentery. The symptoms are stools with pus and fresh blood, abdominal pain, abdominal urgency with rectal heaviness, burning sensation in the anus, thirst with a desire to drink, a red tongue with yellow coating, and a slippery, rapid pulse. |
Pathogenesis | This is a pattern of accumulation and obstruction of damp-heat and epidemic toxins in the large intestine with invasion of heat into the blood level. Damp-heat and epidemic toxins steam the large intestine and burn the adjacent blood vessels, which lead to stools that contain pus and fresh blood. Damp-heat distresses the large intestine and produces a burning sensation in anus. The movement of qi becomes obstructed, which causes abdominal pain and abdominal urgency with rectal heaviness. Heat toxin consumes fluids and causes thirst. A red tongue with a yellow coating and a slippery, rapid pulse are signs of an intense heat toxin. The cause of the pattern is damp-heat and epidemic toxins, and the location of disease is the large intestine and the blood level. Therefore, the therapeutic method is to clear heat, dry dampness, cool the blood, and resolve toxins. |
Application | 1. Essential pattern differentiation Bai Tou Weng Tang is a common formula used to treat heat toxin bloody dysentery. This clinical pattern is marked by stool with pus and fresh blood, abdominal pain, abdominal urgency with rectal heaviness, red tongue body with yellow coating, slippery, rapid pulse. 2. Modern applications This formula may be used in the following biomedically defined disorders when the patient shows signs of intense damp-heat toxins: acute bacillary dysentery, amebic dysentery, and chronic nonspecific ulcerative colitis. |